University of Kentucky
Defining Cell Intrinsic Restriction Factor Activity Detrimental to Tombusviridae Replication
Grade Level at Time of Presentation
Senior
Major
Biotechnology
Institution 23-24
University of Kentucky
KY House District #
85
KY Senate District #
15
Faculty Advisor/ Mentor
Peter Nagy, PhD.
Department
Dept. of Plant Pathology
Abstract
Plant viruses belonging to the Tombusviridae family have relatively small, positive sense (+) RNA genomes. Therefore, the few viral proteins encoded by these genomes must co-opt a variety of host factors to assist in the production of virions. The ongoing evolutionary battle between host organisms and RNA viruses has led to plant antiviral strategies that strive to limit co-opted host factor recruitment and eventual cell exhaustion. Although plants do not have immune responses resembling that of mammalian systems, previous literature has highlighted the presence of innate pathways providing non-specific and immediate responses to pathogens. Plant-infecting tombusviruses serve as excellent models to investigate antiviral activity of cell-intrinsic restriction factors (CIRFs). Recent literature has revealed viral induced gel condensates that are co-localized with viral replication organelles are necessary for complete replication and packaging of progeny (+) RNA. Biomolecular condensates are membraneless organelles that are dynamic in nature as a result of liquid-liquid phase separation. The significant role of viral induced replication condensates has led us to question if antiviral proteins are present in the less protected bio-condensates. Therefore, this project will utilize fluorescence recovery after photobleaching (FRAP) to visualize the ability of fluorescently-tagged antiviral proteins to diffuse into an area of the replication complex subjected to photobleaching. An absence (or very slow) recovery will suggest that antiviral proteins interact with membrane bound components of the VRO. However, medium recovery of fluorescent intensity (approximately 50 % - 60% of the original brightness) within 2 minutes of photobleaching will suggest antiviral agents are able to disrupt the production of progeny (+) RNA via their presence in the more dynamic gel-like condensate. Understanding how host antiviral agents exploit dynamic, viral induced condensates will provide critical knowledge necessary for the development of more efficient antiviral agents that combat viral infection.
Defining Cell Intrinsic Restriction Factor Activity Detrimental to Tombusviridae Replication
Plant viruses belonging to the Tombusviridae family have relatively small, positive sense (+) RNA genomes. Therefore, the few viral proteins encoded by these genomes must co-opt a variety of host factors to assist in the production of virions. The ongoing evolutionary battle between host organisms and RNA viruses has led to plant antiviral strategies that strive to limit co-opted host factor recruitment and eventual cell exhaustion. Although plants do not have immune responses resembling that of mammalian systems, previous literature has highlighted the presence of innate pathways providing non-specific and immediate responses to pathogens. Plant-infecting tombusviruses serve as excellent models to investigate antiviral activity of cell-intrinsic restriction factors (CIRFs). Recent literature has revealed viral induced gel condensates that are co-localized with viral replication organelles are necessary for complete replication and packaging of progeny (+) RNA. Biomolecular condensates are membraneless organelles that are dynamic in nature as a result of liquid-liquid phase separation. The significant role of viral induced replication condensates has led us to question if antiviral proteins are present in the less protected bio-condensates. Therefore, this project will utilize fluorescence recovery after photobleaching (FRAP) to visualize the ability of fluorescently-tagged antiviral proteins to diffuse into an area of the replication complex subjected to photobleaching. An absence (or very slow) recovery will suggest that antiviral proteins interact with membrane bound components of the VRO. However, medium recovery of fluorescent intensity (approximately 50 % - 60% of the original brightness) within 2 minutes of photobleaching will suggest antiviral agents are able to disrupt the production of progeny (+) RNA via their presence in the more dynamic gel-like condensate. Understanding how host antiviral agents exploit dynamic, viral induced condensates will provide critical knowledge necessary for the development of more efficient antiviral agents that combat viral infection.